Research behind lung cancer screening
Large clinical trials established the benefit of low-dose CT screening for people at elevated risk. Guidelines use that evidence to help patients and clinicians decide who should be screened.
The major trials
National Lung Screening Trial
The U.S. trial compared three annual low-dose CT scans with chest X-rays in current and former heavy smokers aged 55 to 74. The CT group had roughly 15–20% fewer deaths from lung cancer. The study established the basis for screening recommendations; its eligibility criteria were narrower than current U.S. guidance.
Read the National Cancer Institute summaryNELSON trial
The Netherlands and Belgium trial compared low-dose CT screening with no screening. At ten years, lung cancer mortality was lower in the screened group of men. The women’s subgroup was smaller, and its estimate had greater uncertainty.
Read the published NELSON abstractOther studies in the ALCSI archive
An Italian randomized trial that examined low-dose CT screening and its longer-term outcomes.
The Danish Lung Cancer Screening Trial contributed evidence about screening intervals and follow-up.
A German screening study with analyses of lung cancer mortality and outcomes by sex.
The UK Lung Cancer Screening Trial used a risk model to select people for screening.
A French feasibility study of how low-dose CT screening could be organized.
An international screening program that has studied protocols for scans and follow-up.
Trial findings do not by themselves determine an individual’s eligibility.
Guidelines and coverage
U.S. Preventive Services Task Force
Recommends annual low-dose CT screening for adults ages 50–80 who have at least 20 pack-years of cigarette-smoking history and currently smoke or quit within the past 15 years. Screening stops when a person has not smoked for 15 years or has a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.
Read the USPSTF recommendationAmerican Cancer Society
Recommends yearly low-dose CT screening for adults ages 50–80 with at least 20 pack-years who currently smoke or smoked in the past. Unlike the USPSTF recommendation, the ACS guideline does not use years since quitting as a cutoff.
Read the ACS guideline summaryMedicare coverage
Medicare’s screening age range differs from the USPSTF recommendation. Coverage also requires no signs or symptoms of lung cancer, a qualifying smoking history, and an order from a healthcare provider. Other insurance plans may have different requirements and follow-up costs.
Check Medicare’s current coverage rules